This invention relates to a wire control device especially adapted for use in the high speed winding of 2-pole stators. However, the invention is not necessarily so limited.
Procedures for winding coils on 2-pole stators with the use of winding forms that are temporarily locked to the unwound stators are described in U.S. Pat. No. RE 25,281 granted to H. W. Moore on Nov. 6, 1962, and U.S. Pat. No. 3,251,559 granted to H. W. Moore on May 17, 1966. A typical 2-pole stator winding machine includes a winding head or shuttle having a pair of wire guide nozzles or needles. Two wires, one for each of the needles, are coursed from a pair of wire supply spools through the shuttle and extend out of the needles. The shuttle is reciprocated to repeatedly pass in opposite directions through the stator core and the winding forms connected thereto. At each end of its reciprocatory travel the shuttle is oscillated about its axis, the direction of oscillation being opposite at opposite ends of the stator. Accordingly, the coil end turns are formed during the oscillatory motions and the coil sides are formed during the reciprocatory motions of the shuttle.
At the beginning of the winding of coils on a stator, the forward ends of the wires are clamped or tied down and the wires exiting from the supply spools are coursed through tensioning and dereeling devices so that, ideally, the wires are under tension throughout the winding operation and the coil turns will closely follow the contours of the winding forms. A typical prior tensioning and dereeling device is shown in U.S. Pat. No. 2,643,075 granted to K. A. Moore on June 23, 1953. Higher speed winding machines require more complete control of the wire tension than can be provided by the device shown in the above K. A. Moore patent. For high speed stator winders, it is desirable also to include a powered wire takeup device which operates in synchronism with the winding shuttle, such a takeup device being shown in the above mentioned U.S. Pat. No. 3,251,559. In general, the wire takeup device shown in the '559 patent draws wire when the winding head is not drawing wire and then releases the wire when the winding head is drawing wire so that there is a more uniform demand for wire from the dereeler. The apparatus shown in the latter patent has been successfully used on stator winding machines having shuttle spindles which operate in the range of 800 or 900 complete strokes per minute.
More recently, stator winding machines having shuttle speeds operating in the range of 1000 to 1250 or more complete strokes per minute are being developed, and it has been discovered that a combination of a dereeling device such as shown in the above mentioned K. A. Moore U.S. Pat. No. 2,643,075 and the powered wire takeup device shown in the H. W. Moore U.S. Pat. No. 3,251,559 do not adequately control the wire tension. As a result, the wire exiting from the winding head may tend to balloon outwardly instead of closely following the guide surfaces which are provided for the wire. The wound coils have loosely formed turns and, especially with fine wire, breakage may occur.
More elaborate tensioning and dereeling devices have been developed especially for high speed winders operating in excess of 800 or 900 complete strokes per minute, one such device being shown in U.S. Pat. No. 4,062,502 granted to K. E. Peck, Jr., on Dec. 13, 1977. However, to date there has been no fully satisfactory tensioning and dereeling device developed for use with a high speed stator winder operating in the range of approximately 1200 complete strokes per minute without the formation of some looseness in the wound coils and occasional wire breakage. Wire breakage is believed to be caused by abrupt reversals in the directions of shuttle movement and also because the wire ballooning outwardly from the shuttle needles snag on parts of the stator being wound or on nearby parts of the machine. It has been suggested to locate shields between the winding needles and parts on which the wires tend to snag. However, so far as known, no fully satisfactory shield has been developed.